


i think i've taught you well

by silver-sparks (Madame_Marauder)



Series: black and silver [1]
Category: Harry Potter - J. K. Rowling
Genre: Fix-It, Other, Professor Regulus Black, Regulus Black Lives, dursley warning for the first chapter, i haven't written any of these characters in literal years so, most characters except Harry and Regulus are background but you know what? thats ok
Language: English
Status: Completed
Published: 2019-06-14
Updated: 2019-06-14
Packaged: 2020-05-07 11:34:25
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 8,691
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19208560
Author URL: https://archiveofourown.org/users/Madame_Marauder/pseuds/silver-sparks
Summary: In which Harry Potter gets a slightly (very) different introduction to the Wizarding World, Regulus Black does not drown but instead discovers a love of academia, and some things go very differently with a competent adult around.Other things... not so much.





	1. diagon alley

**Notes for the Chapter:**

> dursleys/child abuse is referenced several times, fair warning

      It was a perfectly normal day, in a perfectly normal house, on a perfectly normal street. The three perfectly normal members of the perfectly normal family went about their morning, just as they always did.

      A knock sounds at the door.

     "Boy!" Uncle Vernon roars. "Get the door!"

     Harry hurriedly unfolds himself, barely managing to avoid tripping over Dudley's Smeltings stick as he heads into the hallway. Please, let it not be one of the neighbors.

     When he opens the door, a tall man is standing there, hand raised to knock again. He's wearing a crisp white button down, and a matched pinstripe vest and slacks. His hand is resting on a dark wooden cane, and it all makes him look terribly official, even if his hair is rather long.

      "Ah," the man says, clasping his hands together on top of his cane. "You must be Harry Potter."

      Harry can't help but start. "How'd you know my name?"

      The man narrows his eyes slightly, the grey flashing a rather harsh silver, but he doesn't drop his smile. "Well, I have come here to talk to you about a rather special school, you know. Are your aunt and uncle home?"

       "Um," Harry replies. "Yeah, they're having breakfast."

       The man raises an eyebrow. "They are, and you aren't?"

       "I'm done," Harry says quickly. A bit _too_ quickly, if he can judge by the eyebrow inching even further upwards. It isn't a _lie_ , though, he _is_ done with his plain toast.

       "My brother would never stand for this," the man mutters, but shifts his hold on the cane. "Mind if I come in?"

       Harry glances back towards the kitchen, but opens the door to let him in anyway.

       "Who is it, boy?" Aunt Petunia snaps.

       Great. "It's, um, a teacher," Harry calls back hesitantly. The man nods. "He said he wants to talk about my school?"

       His aunt is in the hallway within a single heartbeat. "No! No more freaks in my house!"

       "Hello, Mrs. Dursley," the teacher says calmly. "I'm Professor Leo Sterling, from Hogwarts. I assume you would like to discuss young Harry's school arrangements?"

       Aunt Petunia recoils. "It's _you._ You're that awful boy from the wedding. Freaks, all of you! Go away!"

       Professor Sterling doesn't stop smiling pleasantly. Harry envies his composure. "I'm afraid you're mistaking me for my elder brother, Mrs. Dursley. I was not, in fact, present at your sister's wedding."

       "I don't want to deal with any of your freakish nonsense," Aunt Petunia spits. Harry flinches on instinct. "We're normal people, thank you very much. Get out."

       That just makes Professor Sterling tilt his head. "Before their deaths, the Potters arranged for Harry to attend the most elite magical boarding school in all of Britain. The cost has already been paid, the registration completed. You will not be disturbed by any witch or wizard after this visit, and Harry would be away from September until May."

       Aunt Petunia pauses. "I will not be involved in any of your absurd freakishness."

      "No," Professor Sterling agrees. "You are, after all, not magical. I will take care of any needed arrangements in the wizarding world. This will not cost you a knut- or even a pound. All you will need to do is take him to and from the train station at the start and end of each summer."

       She scowls. "Very well, then. The boy can go. We won't have to put up with him."

       "Petunia?" Vernon calls.

       "We're sending the boy away to his own kind over the school year," Aunt Petunia informs him, then glances back to Harry and Professor Sterling as if they were dirt stains on a good blouse. "Well? Out!"

       Professor Sterling smiles. "I will take Harry to purchase his school supplies, then. He will be back before dark, of course."

      Aunt Petunia scowls even harder.

      "Come along, Harry," Professor Sterling says kindly. "We've got a rather short bus ride ahead of us."

       Harry just blinks, and nods hesitantly. "So- you teach at a school? A _magic_ school? But magic isn't real!"

       "Oh, says who?" Professor Sterling replies lightly, starting down the sidewalk. He does actually lean on his cane, unlike some of the businessmen who only carry one for show. "Here, I'll prove you wrong. Are your glasses broken?"

       Harry goes a little cross-eyed, looking at the tape holding them together. "Yeah."

       Professor Sterling glances around, and then pulls a stick out of his sleeve, tapping it against the arm of his glasses. " _Reparo._ "

       The tape falls off, but the scratches disappear from the lenses, and they no longer sit awkwardly on his face. Harry can't help his gasp.

       "Relatively simple spell," Professor Sterling announces, "but very useful. I think you'll get to that… oh, around third year. Are they better?"

       "Tons," Harry admits. Everything around him seems much, _much_ clearer. Okay. Maybe the professor _isn't_ mad. He'd just done the impossible, after all. "Where are we going?"

       Professor Sterling smiles at him, a real one, not like the polite mask he'd had for Aunt Petunia. "Diagon Alley," he replies. "The central shopping place for all of British Wizardkind. The entrance is in London; we'll be taking a magic bus."

         _Magic bus_ , Harry repeats silently, even as Professor Sterling holds out a hand. A bright purple bus screeches into existence in front of them, and he can't help but flinch back. Professor Sterling just pats his shoulder. "You'll get used to it."

        "Leo!" calls the driver. "How are you? Showing another Muggleborn around?"

        "Very well, thank you, Stan!" Professor Sterling replies, pushing Harry up towards the bus. He climbs the steps hesitantly. "And yes, this one's Hogwarts-bound in September. Leaky Cauldron, if you don't mind."

        The driver grins, as Professor Sterling drops a few coins into a bowl. Bus fare, Harry realizes. "Take your seats, then. You've managed to beat most of the crowd, but we have a few stops ahead of you."

        Professor Sterling steers him towards a seat near the back. "Of course. Harry, here is fine."

        Harry sits, and the moment he does, the bus lurches back into traffic.

        "I'm sorry I couldn't give this to you before your aunt decided to scream at us," Professor Sterling says, pulling a large envelope from a pocket that it really shouldn't have fit in. "But this is your acceptance letter."

        It's addressed to one _Harry J. Potter, the Cupboard Under the Stairs, Little Whinging, Surrey_. Harry tries his best to keep the wax seal intact, but it doesn't quite work.

        He reads over the impossible letter, then reads it again. "But I'm not magic," he whispers. "I'm just Harry."

       "You are," Professor Sterling reassures him. The bus stops, and an old woman with an odd hat steps off. "Have you ever turned things odd colors? Broken or fixed things? Made your hair grow too fast or scrapes heal quickly?"

       After a moment, Harry nods. "I turned my teacher's hair blue. And when Dudley was chasing me, I wanted to be someplace he couldn't get me, and then I was on the roof."

       Professor Sterling raises an eyebrow. "That's very impressive, actually. Good job."

       He'd gotten a week of only bread and water for that, and was locked in his cupboard for most of that time, but he supposes it could be impressive as well.

       "First things first," Professor Sterling decides. "I'll take you to Gringotts, so you can get to your trust vault, and then we can head to get your school robes and potions supplies. We can get your books and wand after lunch, and if you think you can care for her, we'll get you an owl."

       "An owl?" Harry asks.

       Professor Sterling nods. "It's how wizards deliver mail. Now, I'm very sorry to be the one to tell your this, and so quickly, but try to hide your scar. You're rather famous in our world."

      " _Famous_? Me? But I'm just-"

      "There was a wizarding war, ten years ago," Professor Sterling interrupts. His eyes are closed very, very tightly, and his hands are clenched. "The leader of the Dark- his name is Voldemort, but most call him You-Know-Who- attacked your parents. They died. He cast an undeflectable Killing Curse at you, but you didn't die. He did. They call you the Boy-Who-Lived, because your survival ended the war."

      Harry stares. "I killed him? As a baby?"

      "His own Killing Curse reflected off of you and hit him," Professor Sterling says firmly. "We don't know how, but many see you as a hero. Voldemort's fall that night ended the war, and saved countless lives."

      "Leaky Cauldron!" the driver calls out cheerfully.

 

      A few people inside the pub stare at him, but most ignore them. After what Professor Sterling just said, Harry's glad.

      Thankfully, nobody bothers them as his professor guides them through the crowds, muttering explanations for anything that startles him.  There's a lot of explanations needed.

      Gringotts itself is huge, and the goblins are more than a little terrifying. "This is your key," Professor Sterling says, pressing it into his hand as the nauseating cart ride slows down. "Keep it _safe,_ Harry. It's the only way to get to your money."

      Harry nods, and Professor Sterling conjures a leather cord to keep it on for the moment. The goblin watches them with narrowed eyes.

      But then his trust vault is opened, and Harry is almost sick with all the gold and silver inside. All this time of wearing rags, eating scraps, and he's had _this_.

      Professor Sterling walks him through the basics of wizarding money, and how much he'll need for his school list, and how much he should have as spending money. Harry stares at the massive piles of gold, and exhales slowly.

      "Robes and potions," Professor Sterling says cheerfully, pushing him towards one of the most crowded shops.

      The first half of the day passes in a blur of fabric and cauldrons, and then Harry finds himself back in the Leaky Cauldron, a steaming bowl of soup in front of him. Professor Sterling raises an eyebrow from across the table, gesturing with his own spoon. Harry takes the hint, and tries the soup.

      It's easily one of the best things he's ever had, though he's not sure if that's a compliment to magic or an insult to Aunt Petunia. Most likely both.

      Professor Sterling doesn't say anything, and they eat in silence for a few moments, until he finally asks, "Are you enjoying the Wizarding World so far, Harry?"

      Harry nods so quickly that he almost chokes. "Yes! It's amazing. Everything is so- so-"

     "Magical?" Professor Sterling offers dryly.

      " _Yes,_ " Harry agrees. He's too enthusiastic and he knows it, but the teacher just smiles at him and nods. "I can't wait for Hogwarts."

      "If you're this excited to learn, I anxiously await your third year," Professor Sterling replies. "You will make an excellent student, I'm sure of that."

      Harry blinks. "Why my third year?"

      Professor Sterling sighs. "I teach Ancient Runes, which is an elective that you can't take until your third year. It's a harder class than most of the others, except Arithmancy or Transfiguration. Charms is tricky, too, and Potions is all over the place."

       "What are runes?" Harry asks innocently.

       Professor Sterling's eyes spark, and he sits up a little straighter. "It's a bit like the English alphabet, combining letters into words into sentences, and using sentences to give directions," he begins, gesturing wildly with his free hand. "Think about it! Communication is the greatest power of all. Because, see, runes are used to make things stronger, or protect things, and normal magic can't break through them. There's so much potential, Harry, and wizards have only barely begun to explore that potential over the past thousand years."

       It's obvious how much the man loves his subject. But listening to him talk about runes and wand movements and the origins of magic, Harry thinks that he could probably come to love runes too.

      Lunch turns into an incredibly fascinating impromptu lecture, and Harry can't remember being this happy in an incredibly long time.

      Until he steps foot in a wizarding bookstore. "There's so many books!"

      "This is only the first section," Professor Sterling promises. "All your schoolbooks are right here, but I think we can sneak in a couple more, don't you?"

       Harry has to put back about six books that Professor Sterling shakes his head at. "But turning into an animal would be so cool," Harry protests, as his future professor reshelves one of those books.

       "Professor McGonagall may deign to teach you that," Professor Sterling replies. " _After_ you've graduated. It's incredibly advanced and dangerous magic, Harry, and you can certainly learn someday. But not until at least fifth year, alright?"

       Mollified, Harry nods. He ends up with an armful of schoolbooks, and a basic text on runes that's the size of a small brick. Professor Sterling grins when he sees it in his hands, and Harry tries and fails to ignore how his chest aches at the pride in his teacher's expression.

      And then, the moment he's been most excited for, buying a wand.

      Ollivander's is small and dusty and cramped, with an odd old man peering down at him. "Harry Potter, hm? I was wondering when I'd see you, yes. And R-"

     "Leo," Professor Sterling says quickly, but there's an odd tremor in his tone.

      Ollivander narrows his eyes, but nods after a moment. "Yes, I suppose so. You've got more of your brother in you now. Dragon heartstring and aspen, I believe?"

      "It's served me well this past decade," Professor Sterling agrees, relaxing slightly.

      The elderly wandmaker waves his own wand, and a measuring tape floats over to Harry, darting around and recording… something. "I remember when I sold your parents their wands, Mr. Potter," Ollivander says, not even looking at him, sorting through a shelf in the back. "James and Lily Potter, both so unusually matched with their wand woods. Hm. I wonder if you'll be as hard to match as they were."

      Professor Sterling catches his bewildered look, and just shrugs.

      Harry leaves the shop with a holly and phoenix feather wand in his pocket, and a vaguely ominous feeling in his chest. _Why, its brother gave you that scar!_  

     "How about magical ice cream," Professor Sterling offers, looking a little pale himself.

     "Yeah," Harry agrees, and they make one last stop before leaving Diagon Alley.

     Aunt Petunia lets Professor Sterling into the house just long enough to tell her directions to drop Harry off, at the station he's already had explained, and begrudgingly allows him to put Harry's new school trunk away in the cupboard.

      "It'll never fit," Harry whispers.

      Professor Sterling winks, waves his wand, and the inside of the cupboard triples in size. "Magic," he whispers back, and slides the trunk in easily.

      Harry pushes down his threatening laughter. Aunt Petunia hadn't even noticed the man do magic on her own house. "Thank you, professor."

      "I'll see you in September," Professor Sterling promises.

      He only gets a step away before Harry gives in to the urge to hug him.

      "I'll see you soon," Professor Sterling insists, ruffling his hair. "I promise."

      Harry manages a weak smile, and nods.


	2. first year

        Hogwarts is fantastic and amazing and  _ magical _ , and Harry adores it from the moment he sees it from across the lake. As soon as he steps foot in its halls, there's a sense of warmth and brightness blanketing him, and he only barely avoids gasping aloud. 

        And the hat screams  _ Gryffindor _ , and the lions erupt into cheers as his robes turn red and gold, and there's a hundred smiling faces waiting for him as he slides into a seat. Ron comes barrelling over a few minutes later, and Harry is grinning so widely he can hardly breathe.

        Professor Sterling nods at him from the teachers' table, and Ron's brothers immediately start rambling on about finally taking his class.

        Even the headache can't ruin Harry's elation. Not at  _ all. _

        And then there's  _ Quidditch. _

       There is nothing in the world more exhilarating than flying. Nothing at all can compare to the wonder of soaring and falling and recovering at the last second. And somehow, Harry instinctively seems to know exactly what to do.

       His first match, he scours the teachers' section, but Professor Sterling isn't there. He's used to disappointment, though, and locks it away somewhere deep in his chest.

       But then he flies past the small slice of the stands reserved for the families who come to watch their kids play, and amongst the small sprinkling of parents, Professor Sterling is there, next to a scarred man in a sweater. Harry can't linger, not when he's chasing the Snitch, but seeing him there makes his chest ache.

       When his broom is jinxed, it's Professor Sterling that he looks to in a panic. When he falls, it's Professor Sterling on his feet, shouting out some charm that cushions his landing. And when he coughs up the Snitch, it's his friends he looks at first, and Professor Sterling that he glances at second.

       And it's Professor Sterling who asks if he's alright, if he was hurt, if he needed anything. Not Professor McGonagall, nor Madam Pomfrey. It's Professor Sterling who congratulates him on beating his old House, without any hint of bitterness.

       When Harry is caught and given detention after what Hermione delicately calls the Norbert Situation, Professor McGonagall assigns him to Filch. 

      "Minerva," Professor Sterling says, "I'll take them for detention. If there's something in the woods that's killing unicorns, I wouldn't want students near it, and we both know that's where he would have them."

     Professor McGonagall hesitates, but nods.

     "Ah," Professor Sterling says, when they and Malfoy arrive for detention. He is, quite literally, knee-deep in paperwork. "Excellent. Alphabetize this, would you? Everything is labeled in the top left corner."

      "That's not so bad," Ron mutters, thinking of scrubbing cauldrons for Snape.

      Five minutes in, he's changed his mind.

      "This is  _ awful, _ " his friend declares. Malfoy rolls his eyes, but Harry can practically see the steam leaking from his ears, he's so angry to be doing such menial work.

      Professor Sterling nods, not looking up from his book, taking a sip of his hot chocolate as he turns the page. "Indeed."

      Ron heaves another dramatic sigh, and gets back to sorting papers. Hermione is downright  _ enjoying  _ herself, which Harry finds both ridiculous and unfair, but he has to admit that this is better than cleaning bedpans.

      Also, Malfoy doesn't know the alphabet song. He and Hermione do. Ron is glad to learn, as soon as he realizes how much it annoys Malfoy.

      And Professor Sterling, wonderful person that he is, doesn't stop them until Malfoy is almost shaking in rage.

      Harry is pretty sure he's laughing, or at least struggling not to. 

      When the hour of detention is up, they're still nowhere near done. Professor Sterling closes his book, and sets down his mug, fixing them all with a silver-eyed glare. "Alright. Mr Malfoy, you brought up a very good point at the beginning of this. What was it that you said?"

      Malfoy grits his teeth. "That this wasn't something we should be wasting our time on, because there's a spell for it."

     "Precisely," Professor Sterling agrees, and waves a hand at the mess of paper stacks on the floor. "But consider it a metaphor. This is a situation with large and dangerous consequences. An illegally obtained dragon for instance. This is what you can do in the face of a dangerous problem. It's effective, but only after a lot of work, and not without risk of major mistakes."

      Hermione narrows her eyes; Malfoy scowls; Ron frowns.

      "However," Professor Sterling adds, "as Mr Malfoy was so kind to point out, a problem like this can be solved much more easily by a professor."

      He flicks his wand. Every last piece of paper and parchment go fluttering into the air, sorting themselves out. Only a few papers readjust themselves from Ron and Harry's stacks, none from Hermione's, and several from Malfoy's. The stack that forms on the desk is neat, perfect, and done in about five seconds.

      Harry resists the urge to burst out laughing.

      "The same goes for any dangerous situation," Professor Sterling announces. "If it is in any way possible, come to a staff member that you trust for help. Nearly all of us here at Hogwarts will do our best to address the situation. That said, it's getting late, and you ought to return to your Houses. No dragon-related detours, now!"

      Ron complains the entire way back, but Hermione is oddly silent. "What's going on?" Harry finally asks. "You're really quiet."

      "I thought it was rather clever," she admits with a shrug. "It wasn't anything disgusting or dangerous, but he made his point rather well, didn't he?"

      Harry nods, and Ron sighs, but agrees.

_ Trust me when you need help _ , Professor Sterling had all but said.

      And so, months later, it's Professor Sterling that Harry runs to, babbling incoherent nonsense about the Stone.

      "Harry," Professor Sterling says slowly, "I appreciate you coming to me about this. Are you certain that someone is going after this tonight?"

      Harry nods, and opens his mouth, but Professor Sterling shakes his head and stands. "Right. I will investigate this, then. And Mr. Potter?"

      He freezes, because Professor Sterling has  _ never  _ called him that. "Yes?"

       "Please don't attempt to go after it yourselves," his future teacher replies, and starts down the hallway.

       They go after it anyway, because this is Hermione and Ron and Harry, and none of them trust adults. And then they catch up to him in the key room.

       "You know," Professor Sterling says, not even bothering to turn around, "I recall specifically asking you to not follow me. You listen about as well as my brother, apparently."

       Hermione is the one to step forward. "We're sorry, sir, but we didn't know you were coming down here. You said you would investigate, but usually- usually that doesn't mean anything."

      Professor Sterling sighs, glancing up at the keys, then at the door.  _ "Alohomora. _ I understand, Miss Granger. But you will find that there are, in fact, a handful of teachers who take their jobs seriously. I am one of them. Stand back."

      The trio shuffles backwards, and Professor Sterling takes a piece of chalk from his pocket, drawing something on the locked door. "A lesson in practicality," he announces. "Wizards think they're terribly clever, what with their advanced locking spells and charms. But do you know the fastest way to get through a locked door in an emergency?"

       "Pick the lock?" Harry tries.

      "Break the door," Professor Sterling corrects, and points at the runes with his wand, saying something that doesn't sound like English or Latin.

       The door crumbles into dust.

       "Wicked," Ron breathes.

       The troll in the next room is unconscious, thankfully, and the four of them hurry past it, making sure there's a locked door between them and it. "You will stay in this room," Professor Sterling says firmly. "Unless the chess pieces become homicidal, in which case you will stay in the next room, which I'm fairly sure will be safe. Do you understand?"

       "Yes, Professor," they chorus.

      He tries to levitate his cane, and use it like a broomstick, but the chess pieces block his path. "Play," the Black Queen demands.

       Professor Sterling sighs, but transfigures shards of the broken pieces into small white rabbits, one for each missing piece. "Damn it, Minerva. I don't even play."

       Hermione and Harry glance at each other, and then turn to Ron.

       "Uh, Professor," Ron says shakily. "I do."

      That gets a raised eyebrow, before Professor Sterling suddenly looks almost panicked, glancing at the rooms behind him. But after a second or two, the panic settles into anger. "I'm going to be having words with the Headmaster, it seems. Alright, Mr. Weasley. Go ahead."

      Nobody is injured during the game, but Ron and Professor Sterling are both eyeing the chess pieces warily. "Next room?"

       "I would think so," Professor Sterling agrees. "Quickly, now. I don't know how long it will take to reset itself, but I don't want to risk it. Come on."

      They hurry across the board, and into the next room. Hermione immediately fusses over the puzzle, but Professor Sterling shakes his head, casts a charm on his clothes, and steps through the wall of fire.

       From there, it's all a matter of shouting and scuffles. "Regulus Black," an awful voice hisses, and Harry flinches without really knowing why.

       "Oh, Quirinus," comes the reply, full of shaky bravado. "We've been colleagues for months, you know my name is Leo."

       A dry, scraping laugh. "You cannot hide from me, little traitor. You swore yourself to me. You are mine to dispose of. Give me the stone, and I may give you the honor of returning to my side."

       There's a pause. "I am not one of yours, Voldemort! Do you see a mark on my arm? Do you see me bending to kiss your robes? No. You are but a shade, and I am but a teacher."

       "Crucio!" shrieks that high, hissing voice. There's a clatter, like Professor Sterling had dropped his cane, and the sound of someone falling. "No matter who you may be, you will not deny me what is mine!"

       That's about when Hermione shoves a bottle into his hands and Harry goes charging through the fire.

       Professor Sterling is collapsed on the floor, teeth clenched but refusing to scream, and Professor Quirrell is standing over him. Except it's not Professor Quirrell; there's a  _ face  _ on the back of his  _ head _ . 

       "Potter!" the face says. "You, you will fetch me the stone. Or else I will end this precious teacher of yours."

       Harry glances over, from the mirror to Professor Sterling, who is shaking his head. 

       His pocket feels heavier.

       "He has it!" the face wails, and Quirrell lunges at him. But as soon as he touches Harry's arm, he burns. The face keeps shrieking and Quirrell keeps trying and burning and-

       And then Quirrell crumples to the ground, with Professor Sterling standing behind him, holding his cane like a cricket bat.

       "Back of the knees," Professor Sterling manages, gasping for breath. "Are you oka-"

       The unearthly shriek from Quirrell sends them both staggering back, black smoke pouring from the man's body, disappearing as soon as it all escapes.

       "Bloody hell," Professor Sterling breathes, and that's the last thing Harry hears before he blacks out.

 

       He wakes up in the hospital wing, Professor Sterling slumped in the chair beside him, Madam Pomfrey fussing at him. "You were held under the Cruciatus for almost a minute, young man! You need to rest!"

       "I have rested," Professor Sterling insists, even though his voice is hoarse and his skin pale. "I'm perfectly fine. I've had my share of experience with that curse, I'd know if it was a problem- ah. Good morning, Harry."

       "Morning," he manages. "What- what happened? Did Quirrell die? Did I- did I-"

      Professor Sterling waves Madam Pomfrey away, and for once she doesn't even huff at him. "After you blacked out, I froze the flames between the rooms, and carried you through to Mr Weasley and Miss Granger. Your friends were greatly distraught, but helped carry you back to the Hospital Wing, while I brought the unconscious Quirrell. It turns out that since his trip to Albania, he had been possessed by Voldemort; you saw the face on the back of his head, yes?"

     Harry nods.

     "There are two kinds of possession," Professor Sterling says, settling into his teacher voice. "Willing, and unwilling. Once the spirit is exorcised from an unwilling host, the host is usually able to live a long, if traumatized, life. This is because an unwilling possession is only on a surface level, and the spirit is in total control. However, a willing host binds together the souls of themselves and the spirit. Once the spirit is removed from a willing host, they will nearly always perish."

      He already knows the answer, but Harry asks anyway. "And Professor Quirrell was a willing host?"

      "He was," Professor Sterling agrees gently. "He was a very, very willing host. But Voldemort abandoned him after realizing that he would otherwise be captured, and so Quirrell was killed soon after. You did not do it, nor did I, but the possession itself."

       Even so, Harry can't help the way his shoulders curl. But Professor Sterling is there to nod and squeeze his shoulder, and that makes it a little bit better.

**Notes for the Chapter:**

> Yes. Leo Sterling is, in fact, a response and well-adjusted adult. Astonishing.


	3. second year

**Notes for the Chapter:**

> short, and approaching the point of crack

      Harry goes back to the Dursleys, and is rescued by Ron, and flies a car to Hogwarts.

      "Asking adults for help, Harry," Professor Sterling pleads, standing at the end of his bed in the Hospital Wing. "Give it a try. Please."

      Considering that Harry is mostly asleep at the time, he doesn't reply.

      But Professor Sterling leans on his cane, and Harry hears him sigh. It's a rattling, shaky sound, full of concern.

      "Sirius would kill me if I let anything happen to you," Professor Sterling breathes, pausing for another few moments before sighing one more time and walking away. Harry is left with one more thing to mull over in his sleep;  _ who's Sirius? _

       It's a question he would love to ask, but the next time he sees Professor Sterling, there's a petrified cat and a thousand accusations flying around.

       "It's not him," Professor Sterling snaps, after Filch's ranting finally strikes a nerve. "Mrs. Norris is only petrified. She's not dead, nor is she in pain, nor is she in any danger of dying. Calm down."

       Even Snape purses his lips, and nods. "The Mandrake Draught will restore her… once it can be brewed, of course."

       Filch is still shaking with rage, glaring at Harry, but Dumbledore steps in calmly. "Leo, please escort the children down to the feast. Severus, see about our mandrake stores, would you?"

       "Of course," Snape replies, sketching a mocking bow before sweeping away. Professor Sterling frowns after him, but doesn't say a word before turning and waving them down the hallway.

      His friends shaken and silent beside him, Harry takes a deep breath, and manages, "Professor, I didn't-"

      "I know," Professor Sterling agrees. He's pale, and angry. "You couldn't have. I'm sure all the ghosts will support you on that, Harry. This isn't your fault."

       Harry stumbles through the rest of the halls, somehow shocked to have a teacher's support, and silently curses Halloween.

       "Ickle Harrykins," Fred says, swooping in on him a day later. "We've got news for you."

       "Real news," George adds. "From the good professor. Start carrying a mirror in the halls for corners."

       Fred loops an arm around his shoulders. "Sterling is worried about whatever petrified that awful cat, see? Told our class to carry mirrors and to use 'em to look around sharp corners. Figures that if we see the thing that petrified it in the mirror, then it won't hurt us."

       "I'm sure Lockhart has a mirror you can borrow, ickle Harrykins," George agrees, and the twins melt away, snickering.

       The time after that, Professor Sterling is the one petrified.

       There are what Harry vaguely recognizes as protective runes on the back of the mirror in his hand. Hermione is frozen in the bed across from him, clutching a book to her chest, her finger tucked in and marking  a particular page.

       Harry and Ron sit together at Hermione's bedside, but there's a constant stream of visitors in and out of the Hospital Wing. Dozens of Ravenclaws and Hufflepuffs, a sizeable number of Slytherins, and the Weasley twins all stop by to see Professor Sterling.

      "Don't tell McGonagall," George whispers, as Fred adds something to the growing pile of cards and chocolates at the teacher's bedside table. "But Sterling is by far our favorite teacher. Funny and clever, but he actually helps us with a few completely hypothetical ideas."

      "Hypothetical, until we put them into practice, of course," Fred agrees.

     And since he and Ron are visiting Hermione, Harry is in the hospital wing when word arrives of Ginny's disappearance, and the message left on the wall.

      Harry stands there in shock, and then goes to kill a basilisk, and rescue a Weasley. 

      Ron charges in with him, no time to waste on fetching a teacher. McGonagall is handling the crisis, anyway, and Dumbledore is as well.  _ Lockhart _ would hardly be of help, and his office is empty when they run past it, anyway.

      It's Ron who finds his sister, and gathers her in his arms, as Harry stands guard over them both. The boy in the diary laughs and laughs, and shows them his terrible secret.

      " _ I am Lord Voldemort, _ " Tom Riddle declares, as if Harry was incapable of reading the glowing, burning letters. Somewhere, distantly, he's offended.

      "You," Ron says, looking up from Ginny's unconscious body. "Hold on. You, you're V- Voldemort, and your name is Tom Marvolo  _ Riddle _ ? That's not a part of the Sacred Twenty-Eight! That's not even a famous pureblood line!"

      Riddle hisses in utter rage. "You dare-"

      "The pureblood elitist isn't even a pureblood," Ron taunts, climbing to his feet. Harry watches in concern as Riddle narrows his eyes, and raises Ginny's wand.

      Of course, that's before Ron flings himself forward, snatches the wand, and punches the prepubescent Dark Lord in the jaw.

      Harry ignores their shrieks of  _ my little sister _ and  _ filthy blood-traitor _ , and turns back to the diary. It was what had possessed Ginny in the first place, so maybe… " _ Incendio _ !"

       The diary, disappointingly, does not catch fire. That would've been too easy, he guesses.

      Riddle  _ shrieks _ with outrage, though Harry isn't sure if it's because of his attempt at burning the diary or because Ron has him pinned to the disgusting floor, both of them covered in slime and filth from their tussle.

      " _ Speak to me, Slytherin, greatest of the Hogwarts Four,"  _ Riddle demands, and then there's a phoenix and a basilisk and a sword and a fang and a hat.

     Harry draws the Sword of Gryffindor, and it sizzles with the basilisk venom it absorbs off the fangs when he stabs the basilisk through the roof of its mouth. He tosses Ron a broken fang, and his friend stabs the diary, which perishes with a lot of screaming and even more ink. Fawkes cries on Harry's arm, and he narrowly avoids a painful death.

      When Ginny finally stirs, it's Ron who's standing over the diary. It's Ron who carries her and helps support Harry as they stagger out of the Chamber. It's Ron who stumbles into the Hospital Wing, slime in his hair and blood on his robes and his sister in his arms.

      "Ginny!" their mother shrieks.

      She manages a weak smile, and Madam Pomfrey descends on them within seconds.

      "What happened?" someone demands.

      Ron glances at Harry, and Harry glances at Ron.

      "I punched Voldemort," Ron announces with a half-hysterical laugh. "He was- he was in the diary and I punched him. And then Harry killed the basilisk."

      Harry just leans into him, feeling vaguely hysterical himself. "Just a snake. Just a big, ugly snake. You kneed Voldemort in the balls, mate. That deserves some sort of award, I think."

      The entire Weasley family is staring at them in shock. 

      "Special Services to the School," Ron replies, and they both dissolve in hysterical laughter. Madam Pomfrey just sighs.

      Nevermind Ron's impressive heroics, Harry is the one called to see Dumbledore on the last day of attendance, just before the end of year feast. 

      Professor Sterling stands in the Headmaster's Office, pale and staring at the ruined diary sitting before him. "Harry," he says quietly, Dumbledore looking on. "This is a very, very dark piece of magic. Can you tell me  _ exactly  _ what it did?"

      Harry tells him.

      His favorite professor gets paler and paler, and actually jots down a few notes in between bouts of looking worried and looking nauseous. He looks worse with every passing sentence, in fact, as Harry describes Ginny's possession and Tom Riddle's speech. But his eyes widen when Harry explains Ron's fistfight with Voldemort, and his friend stabbing the diary with the fang, and the venom and blood that had coated the Sword of Gryffindor.

      "Albus," Professor Sterling says, looking both very ill and very hopeful, "I heard you were in Gryffindor."

      "Indeed I was," Dumbledore replies, eyes twinkling. "Thank you, Harry, for that enlightening testimony."

      Professor Sterling nods. "Yes. You've done very well, that was very helpful. Thank you, Harry."

      Harry Potter is many things, but he is not a stupid child. "There's more things like that?" he asks. "More that you're trying to destroy?"

      Dumbledore's eyes abruptly stop twinkling, but Professor Sterling just exhales slowly. "Yes. We think there might be more, and we want to get rid of them if there are."

     "Reg-" Dumbledore starts, disapproving.

     " _ Good _ ," Harry interrupts fiercely. "There shouldn't be- the diary was  _ awful _ . If there's another one, it needs to- it needs to be destroyed."

     Professor Sterling looks at him with something like approval. "Right you are, Harry. Items like this are capable of terrible, horrible things, and they need to be stopped."

     The twinkle in the Headmaster's eyes returns full force. "Very well said, my boy. Very well said."

     Harry smiles awkwardly, but nods. 

     "Now," Professor Sterling says. "I'm sure your friends are wondering where you've run off to. Go on."

     Harry grabs his bag, and makes it halfway out the door before turning back and adding, "I'll see you in Runes next year, professor!"

     Professor Sterling's laugh echoes down the stairwell as Harry all but runs, grinning to himself all the way.

     It isn't until he's lying in Dudley's second bedroom, staring at the darkened ceiling, that Harry realizes something.

     Last year, Voldemort had called Professor Sterling someone named  _ Regulus Black _ , and Dumbledore had sounded like he was going to do the same, that day in the office. But Professor Sterling had denied it, so why would Dumbledore call him  _ Regulus  _ instead of  _ Leo _ ?

     Besides, Voldemort had made it sound like this  _ Regulus  _ person had served him, and Professor Sterling isn't blood-purist. He writes on Muggle post-it notes and reads Pride and Prejudice, for Merlin's sake! He's nothing like Malfoy.

      So why call him  _ Regulus _ ?

**Notes for the Chapter:**

> is it crack? or is it ron weasley?


	4. third year

      When Hermione pulls him and Ron into the compartment, Harry looks at the scarred man and blinks.

     "Who's he?" Ron asks, staring a little too hard to be considered subtle.

     "R.J. Lupin," Hermione provides. "He must be the new Defense professor."

      Harry nods, slowly, and wonders why he looks so familiar. "Must be. I think… I think he's friends with Professor Sterling. He came to a Quidditch match, I think."

      Hermione leans forward in her seat. "Really? I'm so excited for Ancient Runes, you know. It seems like a fascinating subject. Did you realize that there are dozens of different runic alphabets? I wonder which kinds we'll be focusing on!"

      "Norse, Elder Futhark, and Celtic," Harry replies, unwrapping his chocolate frog. "And, uh, NEWT courses add the Latinized Futhark."

      Ron stares at him, and Hermione grins.

      "What?" he asks, around a mouthful of chocolate. "Professor Sterling was the one to take me to Diagon before first year. And I may have picked up a couple books…"

       "Harry, that's wonderful!" Hermione exclaims. "Oh, I'm so glad you're taking this class instead of something like Divination."

       He grins awkwardly, and a good share of the train ride is taken up with discussion of classes for next year, cheerfully trading thoughts on summer homework and candy bars. Harry's got plenty left over from his stay in Diagon.

       Of course, then the train stops, and the windows ice over, and the lights go out.

       "We can't be there yet," Ron whispers nervously.

       And then the Dementors arrive, and Harry crumples to the floor, green light behind his eyelids and screams ringing in his ears.

      Hermione shakes him awake, and Lupin gives him a bar of chocolate, and excuses himself extremely quickly.

      Watching him walk away feels like it's torn a chunk out of Harry's chest, and he isn't quite sure why.

      "Please welcome our new DADA teacher, Remus Lupin!" Dumbledore calls out at the feast. Everyone applauds politely, but Professor Sterling is grinning and genuinely seems delighted, and Harry claps a little harder for the man who'd saved him on the train.

      Of course, as soon as Transfiguration lets out for his free period, Malfoy taunts him about Sirius Black coming after him, and Harry knows he's gone pale, but it's not because of the Slytherin in front of him.

_ "Sirius would kill me if I let anything happen to you," Professor Sterling said. "Regulus Black!" Voldemort shrieked. "You listen about as well as my brother, apparently," Professor Sterling sighed. _

       Harry steps back, worldview shattering and realigning itself. The wanted posters; he'd thought they looked familiar, but it wasn't because he'd seen so many.

       It was because Mass-Murderer Sirius Black happens to look a  _ lot  _ like Professor Leo Sterling.

       "Shit," he breathes, and takes off across the castle. There's no Runes class this hour. That's terribly convenient.

       Professor Sterling is staring at a piece of parchment on his desk, already pale, but his face falls even further when he looks up to see Harry in the doorway. "Hello, Harry."

       "You," Harry manages, stepping into the classroom. "You- and him- he called you- you aren't really-"

       "Oh," Professor Sterling replies softly. "Oh, Harry. I'm sorry."

       Somehow, that makes him angrier. "No. You don't- is your real name Regulus Black?"

       Sterling-  _ Black- _ flinches. Not a frown, not a wince, but a full bodily flinch. "That was the name I was born to," he replies, hesitantly, shakily. "But  _ my  _ name, my name is Leo Sterling. I'm not my family."

       "That's not how it works," Harry retorts. He might be crying. He's probably crying. "That's not how it works!"

        "You aren't Harold Dursley," Black- Sterling?- retorts. "You're Harry Potter. Same thing applies."

        That stops him in his tracks. If- if his parents were as bad as the Dursleys, he'd probably change his last name too. And his first name, too, to something less noticeable than  _ Regulus _ .

       "I'm sorry, Harry," Sterling says softly, setting a hand on his shoulder. "I'm so sorry. This wasn't how I wanted you to find out."

       Harry shakes his head. "I won't tell. Not with- you changed it because of him, didn't you? Sirius Black? Your- your-"

        "My brother," Sterling admits. "Seemed like the best one in the family, when he ran off to Gryffindor and then your father. Apparently not. I'll never be able to explain why he did the things he did."

        "I won't tell," Harry repeats. He knows a thing or two about having an awful family.

       Professor Sterling exhales shakily. "Thank you, Harry. Thank you."

       Ron and Hermione ask, but he just shakes his head and says that he remembered that he needed to ask Professor Sterling something important. It's not even a lie.

      When classes start the next day, Harry has the remarkable blessing of having Professor Lupin, Professor Sterling, and Professor McGonagall in a row. He's never had so many competent teachers, nevermind in back-to-back classes.

       He might be able to see where the Ravenclaws are coming from, actually. Especially once Professor Lupin agrees to teach him the Patronus charm.

       It's a very good start to a very good year, and it stays a very good year, right up until the day before Halloween.

       Ron walks into the Runes classroom, because Harry and Hermione have both gotten into an awful habit of staying after class and into lunch to ask extra questions, and Professor Sterling has only just opened his mouth to reply when glowing letters light up against the walls.

       "Um," Ron says.

       Professor Sterling has gone very, very still. "Mr. Weasley. Come in, would you, and turn out your pockets?"

       Harry stares up at the glowing, floating runes. "Is that a ward, Professor?"

      "It is," Professor Sterling replies, still oddly distant. "Can you tell what it's for, either of you?"

      "Some kind of animal," Hermione says immediately, pointing at one of the rune clusters. 

      Ron steps forward, and the wards flare again, never touching him but still announcing a warning. 

      "Notification wards," Harry replies. "It tells you when a certain kind of animal enters the property, but doesn't hurt them, right?"

      "Five points to Gryffindor," Professor Sterling says. "You're both right. It's a demonstration for my NEWT class. But it's not for animals; it's a basic Animagus ward. Mr. Weasley, please turn out your pockets."

       Their friend seems frozen to the spot, but very slowly reaches into his robe pockets, and pulls out Scabbers.

       It goes to hell rather quickly from there.

      Scabbers sees Professor Sterling, wand out, and immediately starts biting and scratching, managing to hit the right nerve to make Ron cry out and drop him. Hermione screams; Harry freezes, tracking the rat's useless sprint for the door that Professor Sterling has already shut.

        " _ Stupefy, _ " Professor Sterling shouts, and it hits the floor just millimeters from Scabbers. His professor curses.

        Hermione whips out a wand and fires off a  _ "Petrificus totalus!"  _ that doesn't quite connect.

        Ron manages a weak, "Bloody hell."

       But it's Harry, with the unerring skill of a Seeker, that sees his chance and takes it, snatching Scabbers out of the air mid-jump. "Gotcha."

       The other three left in the room are staring at him.

       "Alright," Hermione says faintly. "Maybe Quidditch  _ is _ useful, after all."

       Professor Sterling summons a metal box from across the room, runes scratched into the thick walls. "Here. Dump him in.  Voldemort himself couldn't escape from this if he wanted to."

       There's something in his voice that's deadly serious. Harry remembers the diary, and decides he's probably being literal about that statement.

       Professor Sterling mutters something that Harry can't catch, but turns to the silvery dog Patronus that erupts from his wand and says, "McGonagall, Lupin, Snape; come to the Headmaster's Office immediately. Severus, bring Veritaserum.  _ Now. _ "

      The dog barks, and scampers off through a wall.

      "Patronus message," Ron says weakly. "I- you were in the-"

      "No," Professor Sterling replies shortly. "Come on, all of you. Thank Merlin it's lunch hour. This is not something to wait around on."

      Hermione hurries after him as he sweeps out the door, and Harry pulls Ron along after him. "It's just Scabbers," his best friend whispers. "He's not an Animagus. He can't be, Harry. He can't be."

      "I know," Harry mutters back. Professor Sterling is stiff and cold with rage, storming down the hallway. "But I trust the professor's wards. There's something wrong."

      Snape meets them at the entrance to Dumbledore's office. "What's all this about? More bumbling Gryffindors causing havoc?"

      "The  _ rat _ , potentially," Professor Sterling replies, just as coldly. "Tripped the Animagus ward that Minerva and I set up for the NEWT classes."

       The two men exchange a look, before Snape turns to the statue and snarls out, "Dubble Bubble."

       Harry fights back a smile- this is not a good situation, it'd only get him in trouble- and follows the others up the stairs.

       "R- Leo," Professor Lupin says, looking at their ragtag group with concern, "I'm a little afraid to ask what this is about."

      "You'll see," Professor Sterling snaps, setting the box down on Dumbledore's heavy oak desk, cracking the lid open just enough to aim his wand. " _ Stupefy. Petrificus totalus." _

      Dumbledore laces his fingers together, peering at the box. "Does this concern our project, my boy?"

      "Not in the slightest," Professor Sterling admits. "No. But as Minerva can attest, she and I have been doing a demonstration of the basic Animagus ward for my classes all week. When Ron Weasley entered the classroom, something in his pockets tripped that ward."

      Professor Lupin has suddenly gone pale, and McGonagall looks incensed. "An Animagus masquerading as a pet? That's unthinkable!"

       "Indeed," Snape agrees, tone as oily as his hair. "Especially since it appears to be one of  _ your  _ students involved, Minerva."

       She glares at him, but Professor Sterling just upends the box onto the desk, and mutters a quick set of spells that Harry can't quite hear. Ron turns away, and Hermione inhales sharply.

       The rat becomes a man, immediately held by golden ropes and several spells.

       He's still very ratlike, in the beady eyes and twitchy nose. "Ah," he squeaks. "I- I- thank you for turning me back! Sirius Black, he- he-"

      Professor Lupin is standing behind him, and there's a furious edge to his tone as he calmly says, "Don't lie,  _ Wormtail _ ."

      Snape takes the man's shock as an opportunity to dose him with the Veritaserum. "It makes you tell the truth," Hermione whispers, as they watch the man try to squirm away from Snape, only to meet the drawn wands of both Sterling and Lupin. "Lying is impossible, if you word the questions right."

      "What is your full legal name?" Dumbledore asks calmly.

      "P- Peter Pettigrew," the former Scabbers stutters out.

     There's a chorus of gasps and sharp inhales, Ron and Hermione both one of them. "He's why Black went to prison, for killing him and a bunch of Muggles," Ron manages.

     "Were you the Secret Keeper for James and Lily Potter at the time of their deaths?" Professor Lupin asks, tone pained.

      "N- n- yes," Pettigrew replies, eyes wide and panicked as he tries to fight the Veritaserum. "Yes."

     Professor Sterling readjusts his grip on his wand. "Did you knowingly and willingly betray the Secret of James and Lily Potter's whereabouts to the Dark Lord Voldemort?"

      "N- yes!" Pettigrew confesses. 

     If not for the way Ron clings to him, the grip that Hermione has on his arm, Harry would go charging at him in a fury.

     "Did Sirius Black in any way betray James and Lily Potter to Lord Voldemort?" Professor Sterling continues.

     "No!" Pettigrew sounds almost delighted. "But he got what he deserved, filthy mutt!"

      Professor Lupin has murder in his eyes, but seems utterly composed otherwise. Professor Sterling is as tense as a drawn bow, but his eyes are flat and cold.

     "Albus," Professor Sterling says calmly. "Call the Aurors, withdraw the Dementors from the grounds, and lock this pathetic vermin out of his Animagus form."

     Dumbledore stands, and draws his wand. "I will do so gladly."

     As soon as the Aurors come through the Floo, Professor Sterling walks over, and sets a hand on Ron's shoulder. "I'm so sorry."

      "I'm just glad you caught him," Ron declares fiercely, before bursting into tears.

 

     The trial of Peter Pettigrew is held on November 2nd, 1993. An innocent man is exonerated,  _ in absentia _ , and a guilty one sentenced to hell on earth. The Prophet screams it in headline after headline, in special evening editions and in pages and pages of the morning news. Dumbledore makes a speech.

       Professor Lupin casts a Patronus brighter than Harry's ever seen, and whispers to it. The odd wolf goes loping through the air, gaining speed as it charges through a wall, snatching a copy of the Prophet in its mouth as it races down the hall and out an open window.

       Professor Sterling takes his cane, and slowly heads down to the lake, waiting.

       Eventually, Professor Lupin returns, a massive black dog trotting along at his side. But as soon as the dog sees Professor Sterling, it freezes, Lupin barely coaxing it onwards.

       But then the dog, too, becomes a man, thin and frail and ragged. A man no longer wanted, no longer hunted, but disbelieving all the same. He steps forward hesitantly, saying something that Harry can't hear from where he's waiting.

        Professor Sterling stands, and replies, the wind stealing his words away and carrying along  _ I'm so sorry _ from the valley to the castle.

       Sirius Black takes another disbelieving step, and another, and is met halfway by his waiting brother. And Regulus Black weeps as he embraces his brother for the first time in nearly two decades.

 

        All is not well, not yet, but it will be in time.

**Notes for the Chapter:**

> tada there we go, my first posted hp fic in like two years, yay me
> 
> drop a kudos or comment if you enjoyed, please!


End file.
